Answer:
Energy flow in an ecosystem is unidirectional. It means that energy which is absorbed by the producers from sun and is converted into chemical energy, always flow from a lower trophic level to a higher trophic level as in a food chain when herbivore consumes producers the energy is transferred from producers to consumers and so on. Some of this energy is assimilated some is used by the organism and some is dessipated in the environment but the flow of energy is never reverted, that is obviously a producer can not consume a consumer.
Answer:
They are neutrophils, eosinophils, basophils, lymphocytes, and monocytes.
Out of these ones the T-cells are responsible for recognizing antigens on the surface.
Explanation:
T cells
Killer T cells
Killer or cytotoxic T cells scan the surface of cells in the body to see if they have become infected with germs, or if they have turned cancerous. If so, they kill these cells.
Helper T cells
Helper T cells "help" other cells in the immune system to start and control the immune response against foreign substances.
Regulatory T cells or Tregs
Tregs control or suppress other cells in the immune system. They have both helpful and harmful effects.
Memory T cells
Natural killer T cells
The best estimate<span> for </span>Earth's age<span> is based on radiometric dating of fragments from the Canyon Diablo iron meteorite. From the fragments, </span>scientists calculated<span> the relative abundances of elements that formed as radioactive uranium decayed over billions of years.</span>
Answer:
e. spores
Explanation:
In the given question, the characteristics of a plant are mentioned which are the dominant sporophyte, cell wall and the Chl a or b.
It is mentioned that the plant has a dominant sporophyte therefore it produces the spores during its life cycle. The other features like the endosperm, seeds, flowers are the characteristics on the basis of which the plant can be characterised as they differ in the plants.
Since the production of spores is a characteristic feature of the sporophyte, therefore, it will be least considered by the botanist to discover a new species.
Thus, Option-E is the correct answer.
Initiative vs. guilt
<span>Erikson's stage of initiative vs. guilt occurs
to children between the ages of 3 and 6. This stage is the third stage of Erikson’s
theory of psychosocial development. According to this theory, children need to
start exercising control and power over the things that influence their lives
and their environment.</span>